384 sr.MMAUY OF CURRENT RESEARCHES RELATING TO 



in nomenclature and also in our conception of certain species is necessary. 

 Many species have been named over and over again by different, or by 

 the same, botanists. Consequently, about a third of the species have to 

 be reduced ; yet a few species, long regarded as synonyms, have to be 

 resuscitated. After criticising the various methods of classification 

 of leading authors, and calling for something more natural, he expresses 

 a belief in such characters as : rauienta on rhizome, position of sori, 

 direction of pinna? (especially the lowest pair), margin of frond and 

 texture. He gives descriptions of thirty-nine species with varieties, 

 synonyms, etc. 



Terns of the Andes.* — W. R. Maxon, in reporting on a collection 

 of Pteridophytes gathered by J. X. Rose in Peru, Bolivia and Chile, 

 gives a list of twenty-six species, six of which are new to science. He 

 describes the characteristic structure of these, and adds critical notes. 

 The rather high proportion of new species suggests the need of further 

 botanical exploration in the Andes. 



Bryophyta. 



(By A. Gepp.) 



Archegonium of Sphagnum subsecundum.t— G-. S.Bryan describes 

 the development of the archegonium of Sphagnum subsecundum. In 

 his summary he says that : — 1. Sex-organs were produced iu vast 

 quantities in the autumn of 1912-18 in an Indiana bog. 2. At maturity 

 the archegonial and antheridial heads are readily distinguished, and the 

 former may be recognized by the coloured bud in the middle. This bud 

 contains terminal archegonia on short side branches. 3. The archegonia 

 begin to develop in September. 4. The apical cell of a side branch is a 

 primordium ; each of the two last-formed segments becomes the initial 

 of a secondary archegonium, while that part of the apical cell above, and 

 not included by these segments, is the initial of the primary archegonium. 

 5. The early stages of development of the primary archegonium show 

 great irregularity ; there may be a filament of cells by successive trans- 

 verse divisions of the apical cell— or growth by an apical cell with two 

 cutting faces— or a mixture of planes. 6. The secondary archegonium 

 develops only by successive transverse divisions. 7. The archegonium 

 proper is initiated in the usual Bryophyte manner. In the terminal 

 cells three oblique walls cut off three peripheral segments and originate 

 the primary axial cell within, which dividing gives rise to cover cell and 

 central celf. The cover cell is relatively inactive and cuts off no basal 

 segments. 9. The central cell on division forms the primary neck 

 canal cell (mother-cell of neck canal row) and the primary ventral cell. 

 10. The growth of the neck canal row is intercalary, the cells dividing 

 in almost any order. 11. The primary ventral cell divides late into 

 ventral canal cell and egg. 12. The growth of the wall cells of the 

 archegonium is intercalary. 13. The mature archegonium has eight or 



* Smithsonian Misc. Coll., lxv. No. 8 (Washington, 1915) 12 pp. 

 t Bot. Gaz., lix. (1915) pp. 40-56 (4 pis.). 



